This invention relates generally to controlling sharing of files by portable devices, and, more particularly, to controlling sharing of music files by portable music players.
Personal electronic devices of various types have become prevalent in everyday use. For example, it is not uncommon to find consumers today using cellular phones, personal digital assistants (PDAs), pagers, portable music players such as MP3 (Moving Pictures Expert Group, Layer 3) players, and other types of music players.
The availability of digital music today may be one reason portable music players have become popular amongst music fans. In some cases, digital music is stored in digital files that may be readily exchanged by users. Currently, transferring digital music files from one music player to another typically involves a host, usually a personal computer or network. For example, a user may transfer a music file from a host to one or more music players. Transfers may include making copies of the file, or, alternatively, moving the original file.
To discourage unauthorized copying and playing of digital audio content, a variety of secure mechanisms have been proposed, including Secure Digital Music Initiative (SDMI). The SDMI Portable Device Specification Part 1, Version 1.0, document No. pdwg99070802, published Jul. 8, 1999. While SDMI may contribute in reducing unauthorized transfers of files from a host computer to a portable music device, it may not necessarily be as effective in controlling unauthorized transfers of music files between portable music devices.
Thus, there is a need to control sharing of music files by portable music devices.